%0 Journal Article
%9 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES
%A Balan, E.
%A Fritsch, Emmanuel
%A Radtke, G.
%A Paulatto, L.
%A Juillot, Farid
%A Baron, F.
%A Petit, S.
%T First-principles modeling of the infrared spectrum of Fe- and Al-bearing lizardite
%D 2021
%L fdi:010083291
%G ENG
%J European Journal of Mineralogy
%@ 0935-1221
%M ISI:000711975100001
%N 5
%P 647-657
%R 10.5194/ejm-33-647-2021
%U https://www.documentation.ird.fr/hor/fdi:010083291
%> https://horizon.documentation.ird.fr/exl-doc/pleins_textes/2021-12/010083291.pdf
%V 33
%W Horizon (IRD)
%X The theoretical vibrational properties of a series of Fe- and Al-bearing lizardite models have been determined at the density functional theory level. Each periodic model displays a single cationic impurity substituted at an octahedral or tetrahedral site of a supercell of lizardite (Mg3Si2O5(OH)(4)) containing 162 atoms. The isovalent Fe2+ for Mg2+ substitution has been considered, as well as the heterovalent substitution of Fe3+ or Al3+ for Mg2+ or Si4+. Comparison of the theoretical absorption spectra with previously reported experimental spectra of natural and laboratory-grown lizardite samples allows us to propose an interpretation for most of the observed bands. Although the identification of specific bands related to octahedral Fe2+ in FTIR spectra is challenging, broad bands at 3584 and 3566 cm(-1) reflect the occurrence of octahedral Al3+ and Fe3+, respectively, in the natural samples. These broad bands likely overlap with potential contribution related to tetrahedral Al3+. It is suggested that the modification of the H-bonding pattern related to the incorporation of trivalent ions at tetrahedral sites has an overall broadening effect on the interlayer-OH stretching bands of lizardite.
%$ 064 ; 020